Disease Trends and Reporting

There is no national reporting or surveillance system for Mycoplasma pneumoniae infections.

Estimated incidence

M. pneumoniae infections are common, but the true number of people affected is unknown. An estimated 2 million cases of M. pneumoniae infections occur each year in the United States.

Trends over time

The number of M. pneumoniae infections varies over time, with peaks of disease every 3 to 7 years. This illness can happen any time during the year but may be more common in summer and early fall.


Outbreaks occur mostly in crowded environments like college residence halls and nursing homes. Outbreaks can be prolonged due to the long incubation period of M. pneumoniae.